3 * $Id: tripe.h,v 1.14 2003/04/06 10:36:33 mdw Exp $
5 * Main header file for TrIPE
7 * (c) 2001 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Trivial IP Encryption (TrIPE).
14 * TrIPE is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * TrIPE is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with TrIPE; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 /*----- Revision history --------------------------------------------------*
32 * Revision 1.14 2003/04/06 10:36:33 mdw
33 * Rearrange so as not to include Linux headers unless we need to.
35 * Revision 1.13 2003/04/06 10:26:35 mdw
36 * Report peer name on decrypt errors.
38 * Revision 1.12 2003/04/06 10:25:17 mdw
39 * Support Linux TUN/TAP device. Fix some bugs.
41 * Revision 1.11 2002/01/13 14:57:42 mdw
44 * Revision 1.10 2002/01/13 14:54:58 mdw
47 * Revision 1.9 2001/06/22 19:40:36 mdw
48 * Support expiry of other peers' public keys.
50 * Revision 1.8 2001/06/19 22:10:57 mdw
51 * Some more constants for the algorithms. Document the packet format
52 * change for non-malleability. Moved @buf@ definitions to separate header
55 * Revision 1.7 2001/03/03 12:07:08 mdw
56 * Rename word get and put functions now that there's 16-bit support.
58 * Revision 1.6 2001/02/19 19:11:09 mdw
59 * Output buffering on admin connections.
61 * Revision 1.5 2001/02/16 21:41:43 mdw
62 * Major changes. See source files for details.
64 * Revision 1.4 2001/02/05 19:56:37 mdw
65 * Sequence number protection, and BSD tunnels.
67 * Revision 1.3 2001/02/04 01:17:55 mdw
68 * Create a configuration header file to tidy up command lines.
70 * Revision 1.2 2001/02/03 22:40:29 mdw
71 * Put timer information into the entropy pool when packets are received
72 * and on similar events. Reseed the generator on the interval timer.
74 * Revision 1.1 2001/02/03 20:26:37 mdw
86 /*----- Header files ------------------------------------------------------*/
101 #include <sys/types.h>
102 #include <sys/time.h>
105 #include <sys/stat.h>
107 #include <sys/socket.h>
109 #include <netinet/in.h>
110 #include <arpa/inet.h>
116 #include <mLib/alloc.h>
117 #include <mLib/arena.h>
118 #include <mLib/bres.h>
119 #include <mLib/dstr.h>
120 #include <mLib/env.h>
121 #include <mLib/fdflags.h>
122 #include <mLib/fwatch.h>
123 #include <mLib/mdwopt.h>
124 #include <mLib/quis.h>
125 #include <mLib/report.h>
126 #include <mLib/sel.h>
127 #include <mLib/selbuf.h>
128 #include <mLib/sig.h>
129 #include <mLib/str.h>
130 #include <mLib/sub.h>
131 #include <mLib/trace.h>
133 #include <catacomb/gcipher.h>
134 #include <catacomb/gmac.h>
135 #include <catacomb/grand.h>
136 #include <catacomb/key.h>
137 #include <catacomb/paranoia.h>
139 #include <catacomb/noise.h>
140 #include <catacomb/rand.h>
142 #include <catacomb/mp.h>
143 #include <catacomb/mpmont.h>
144 #include <catacomb/mprand.h>
145 #include <catacomb/dh.h>
152 /*----- Magic numbers -----------------------------------------------------*/
154 /* --- Tunnel types --- */
161 /* --- Trace flags --- */
169 #define T_KEYEXCH 64u
170 #define T_KEYMGMT 128u
176 #define SEC(n) (n##u)
177 #define MIN(n) (n##u * 60u)
178 #define MEG(n) (n##ul * 1024ul * 1024ul)
180 /* --- Other things --- */
182 #define PKBUFSZ 65536
184 /*----- TrIPE protocol ----------------------------------------------------*/
186 /* --- TrIPE message format --- *
188 * A packet begins with a single-byte message type. The top four bits are a
189 * category code used to send the message to the right general place in the
190 * code; the bottom bits identify the actual message type.
193 #define MSG_CATMASK 0xf0
194 #define MSG_TYPEMASK 0x0f
196 /* --- Encrypted message packets --- *
198 * Messages of category @MSG_PACKET@ contain encrypted network packets. The
199 * message content is a symmetric-encrypted block (see below). Reception of
200 * a packet encrypted under a new key implicitly permits that key to be used
201 * to send further packets.
203 * The only packet type accepted is zero.
205 * Packets may be encrypted under any live keyset, but should use the most
209 #define MSG_PACKET 0x00
211 /* --- Key exchange packets --- */
213 #define MSG_KEYEXCH 0x10
215 #define KX_PRECHAL 0u
220 #define KX_SWITCHOK 5u
223 /* --- Symmetric encryption and keysets --- *
225 * Packets consist of an 80-bit MAC, a 32-bit sequence number, and the
228 * The plaintext is encrypted using Blowfish in CBC mode with ciphertext
229 * stealing (as described in [Schneier]. The initialization vector is
230 * selected randomly, and prepended to the actual ciphertext.
232 * The MAC is computed using the HMAC construction with RIPEMD160 over the
233 * sequence number and the ciphertext (with IV); the first 80 bits of the
234 * output are used. (This is the minimum allowed by the draft FIPS for HMAC,
235 * and the recommended truncation.)
237 * A keyset consists of
239 * * an integrity (MAC) key;
240 * * a confidentiality (encryption) key; and
241 * * a sequence numbering space
243 * in each direction. The packets sent by a host encrypted under a
244 * particular keyset are assigned consecutive sequence numbers starting from
245 * zero. The receiving host must ensure that it only accepts each packet at
246 * most once. It should maintain a window of sequence numbers: packets with
247 * numbers beyond the end of the window are accepted and cause the window to
248 * be advanced; packets with numbers before the start of the window are
249 * rejected; packets with numbers which appear within the window are accepted
250 * only if the number has not been seen before.
252 * When a host sends a @KX_SWITCH@ or @KX_SWITCHOK@ message, it installs the
253 * newly-negotiated keyset in a `listen-only' state: it may not send a packet
254 * encrypted under the keyset until either it has received a @KX_SWITCH@ or
255 * @KX_SWITCHOK@ message, or a @MSG_PACKET@ encrypted under the keyset, from
259 /*----- Cipher selections -------------------------------------------------*/
261 #include <catacomb/blowfish.h>
262 #include <catacomb/blowfish-cbc.h>
263 #include <catacomb/blowfish-counter.h>
264 #include <catacomb/rmd160.h>
265 #include <catacomb/rmd160-hmac.h>
267 #define CIPHER (&blowfish_cbc)
268 #define MAC (&rmd160_hmac)
270 #define HASH_CTX rmd160_ctx
271 #define HASH_INIT rmd160_init
272 #define HASH rmd160_hash
273 #define HASH_STRING(c, s) HASH((c), s, sizeof(s))
274 #define HASH_DONE rmd160_done
275 #define HASHSZ RMD160_HASHSZ
277 #define MGF_CTX blowfish_counterctx
278 #define MGF_INIT blowfish_counterinit
279 #define MGF_CRYPT blowfish_counterencrypt
282 #define IVSZ BLOWFISH_BLKSZ
285 /*----- Data structures ---------------------------------------------------*/
287 /* --- Socket addresses --- *
289 * A magic union of supported socket addresses.
294 struct sockaddr_in sin;
297 /* --- A symmetric keyset --- *
299 * A keyset contains a set of symmetric keys for encrypting and decrypting
300 * packets. Keysets are stored in a list, sorted in reverse order of
301 * creation, so that the most recent keyset (the one most likely to be used)
304 * Each keyset has a time limit and a data limit. The keyset is destroyed
305 * when either it has existed for too long, or it has been used to encrypt
306 * too much data. New key exchanges are triggered when keys are close to
310 typedef struct keyset {
311 struct keyset *next; /* Next active keyset in the list */
312 unsigned ref; /* Reference count for keyset */
313 struct peer *p; /* Pointer to peer structure */
314 time_t t_exp; /* Expiry time for this keyset */
315 unsigned long sz_exp; /* Data limit for the keyset */
316 T( unsigned seq; ) /* Sequence number for tracing */
317 unsigned f; /* Various useful flags */
318 gcipher *cin, *cout; /* Keyset ciphers for encryption */
319 gmac *min, *mout; /* Keyset MACs for integrity */
320 uint32 oseq; /* Outbound sequence number */
321 uint32 iseq, iwin; /* Inbound sequence number */
324 #define KS_SEQWINSZ 32 /* Bits in sequence number window */
326 #define KSF_LISTEN 1u /* Don't encrypt packets yet */
327 #define KSF_LINK 2u /* Key is in a linked list */
329 /* --- Key exchange --- *
331 * TrIPE uses the Wrestlers Protocol for its key exchange. The Wrestlers
332 * Protocol has a number of desirable features (e.g., perfect forward
333 * secrecy, and zero-knowledge authentication) which make it attractive for
334 * use in TrIPE. The Wrestlers Protocol was designed by Mark Wooding and
341 typedef struct kxchal {
342 struct keyexch *kx; /* Pointer back to key exchange */
343 mp *c; /* Responder's challenge */
344 mp *r; /* My reply to the challenge */
345 keyset *ks; /* Pointer to temporary keyset */
346 unsigned f; /* Various useful flags */
347 sel_timer t; /* Response timer for challenge */
348 octet hc[HASHSZ]; /* Hash of his challenge */
349 mp *ck; /* The check value */
350 octet hswrq_in[HASHSZ]; /* Inbound switch request message */
351 octet hswok_in[HASHSZ]; /* Inbound switch confirmation */
352 octet hswrq_out[HASHSZ]; /* Outbound switch request message */
353 octet hswok_out[HASHSZ]; /* Outbound switch confirmation */
356 typedef struct keyexch {
357 struct peer *p; /* Pointer back to the peer */
358 keyset **ks; /* Peer's list of keysets */
359 unsigned f; /* Various useful flags */
360 unsigned s; /* Current state in exchange */
361 sel_timer t; /* Timer for next exchange */
362 dh_pub kpub; /* Peer's public key */
363 time_t texp_kpub; /* Expiry time for public key */
364 mp *alpha; /* My temporary secret */
365 mp *c; /* My challenge */
366 mp *rx; /* The expected response */
367 unsigned nr; /* Number of extant responses */
368 time_t t_valid; /* When this exchange goes bad */
369 octet hc[HASHSZ]; /* Hash of my challenge */
370 kxchal *r[KX_NCHAL]; /* Array of challenges */
373 #define KXF_TIMER 1u /* Waiting for a timer to go off */
374 #define KXF_DEAD 2u /* The key-exchanger isn't up */
375 #define KXF_PUBKEY 4u /* Key exchanger has a public key */
378 KXS_DEAD, /* Uninitialized state (magical) */
379 KXS_CHAL, /* Main answer-challenges state */
380 KXS_COMMIT, /* Committed: send switch request */
381 KXS_SWITCH /* Switched: send confirmation */
384 /* --- Tunnel structure --- *
386 * Used to maintain system-specific information about the tunnel interface.
389 #if TUN_TYPE == TUN_LINUX
390 # include <linux/if.h>
391 # include <linux/if_tun.h>
394 typedef struct tunnel {
395 #if TUN_TYPE == TUN_UNET
396 sel_file f; /* Selector for Usernet device */
397 struct peer *p; /* Pointer to my peer */
398 #elif TUN_TYPE == TUN_LINUX
399 sel_file f; /* Selector for TUN/TAP device */
400 struct peer *p; /* Pointer to my peer */
401 char ifn[IFNAMSIZ]; /* Interface name buffer */
402 #elif TUN_TYPE == TUN_BSD
403 sel_file f; /* Selector for tunnel device */
404 struct peer *p; /* Pointer to my peer */
405 unsigned n; /* Number of my tunnel device */
407 # error "No support for this tunnel type"
411 /* --- Peer statistics --- *
413 * Contains various interesting and not-so-interesting statistics about a
414 * peer. This is updated by various parts of the code. The format of the
415 * structure isn't considered private, and @p_stats@ returns a pointer to the
416 * statistics block for a given peer.
419 typedef struct stats {
420 unsigned long sz_in, sz_out; /* Size of all data in and out */
421 unsigned long sz_kxin, sz_kxout; /* Size of key exchange messages */
422 unsigned long sz_ipin, sz_ipout; /* Size of encapsulated IP packets */
423 time_t t_start, t_last; /* Time peer created, last recv */
424 unsigned long n_reject; /* Number of rejected packets */
425 unsigned long n_in, n_out; /* Number of packets in and out */
426 unsigned long n_kxin, n_kxout; /* Number of key exchange packets */
427 unsigned long n_ipin, n_ipout; /* Number of encrypted packets */
430 /* --- Peer structure --- *
432 * The main structure which glues everything else together.
435 typedef struct peer {
436 struct peer *next, *prev; /* Links to next and previous */
437 char *name; /* Name of this peer */
438 tunnel t; /* Tunnel for local packets */
439 keyset *ks; /* List head for keysets */
440 buf b; /* Buffer for sending packets */
441 addr peer; /* Peer socket address */
442 size_t sasz; /* Socket address size */
443 stats st; /* Statistics */
444 keyexch kx; /* Key exchange protocol block */
447 /* --- Admin structure --- */
449 #define OBUFSZ 16384u
451 typedef struct obuf {
452 struct obuf *next; /* Next buffer in list */
453 char *p_in, *p_out; /* Pointers into the buffer */
454 char buf[OBUFSZ]; /* The actual buffer */
457 typedef struct admin {
458 struct admin *next, *prev; /* Links to next and previous */
459 unsigned f; /* Various useful flags */
461 unsigned seq; /* Sequence number for tracing */
463 char *pname; /* Peer name to create */
464 char *paddr; /* Address string to resolve */
465 obuf *o_head, *o_tail; /* Output buffer list */
466 selbuf b; /* Line buffer for commands */
467 sel_file w; /* Selector for write buffering */
468 bres_client r; /* Background resolver task */
469 sel_timer t; /* Timer for resolver */
470 addr peer; /* Address to set */
471 size_t sasz; /* Size of the address */
474 #define AF_DEAD 1u /* Destroy this admin block */
475 #define AF_LOCK 2u /* Don't destroy it yet */
477 /*----- Global variables --------------------------------------------------*/
479 extern sel_state sel; /* Global I/O event state */
480 extern dh_priv kpriv; /* Our private key */
481 extern mpmont mg; /* Montgomery context for DH group */
482 extern octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ];
485 extern const trace_opt tr_opts[]; /* Trace options array */
486 extern unsigned tr_flags; /* Trace options flags */
489 /*----- Other macros ------------------------------------------------------*/
491 #define TIMER noise_timer(RAND_GLOBAL)
493 /*----- Key management ----------------------------------------------------*/
495 /* --- @km_interval@ --- *
499 * Returns: Zero if OK, nonzero to force reloading of keys.
501 * Use: Called on the interval timer to perform various useful jobs.
504 extern int km_interval(void);
506 /* --- @km_init@ --- *
508 * Arguments: @const char *kr_priv@ = private keyring file
509 * @const char *kr_pub@ = public keyring file
510 * @const char *tag@ = tag to load
514 * Use: Initializes, and loads the private key.
517 extern void km_init(const char */*kr_priv*/, const char */*kr_pub*/,
518 const char */*tag*/);
520 /* --- @km_getpubkey@ --- *
522 * Arguments: @const char *tag@ = public key tag to load
523 * @dh_pub *kpub@ = where to put the public key
524 * @time_t *t_exp@ = where to put the expiry time
526 * Returns: Zero if OK, nonzero if it failed.
528 * Use: Fetches a public key from the keyring.
531 extern int km_getpubkey(const char */*tag*/, dh_pub */*kpub*/,
534 /*----- Key exchange ------------------------------------------------------*/
536 /* --- @kx_start@ --- *
538 * Arguments: @keyexch *kx@ = pointer to key exchange context
542 * Use: Stimulates a key exchange. If a key exchage is in progress,
543 * a new challenge is sent (unless the quiet timer forbids
544 * this); if no exchange is in progress, one is commenced.
547 extern void kx_start(keyexch */*kx*/);
549 /* --- @kx_message@ --- *
551 * Arguments: @keyexch *kx@ = pointer to key exchange context
552 * @unsigned msg@ = the message code
553 * @buf *b@ = pointer to buffer containing the packet
557 * Use: Reads a packet containing key exchange messages and handles
561 extern void kx_message(keyexch */*kx*/, unsigned /*msg*/, buf */*b*/);
563 /* --- @kx_free@ --- *
565 * Arguments: @keyexch *kx@ = pointer to key exchange context
569 * Use: Frees everything in a key exchange context.
572 extern void kx_free(keyexch */*kx*/);
574 /* --- @kx_newkeys@ --- *
576 * Arguments: @keyexch *kx@ = pointer to key exchange context
580 * Use: Informs the key exchange module that its keys may have
581 * changed. If fetching the new keys fails, the peer will be
582 * destroyed, we log messages and struggle along with the old
586 extern void kx_newkeys(keyexch */*kx*/);
588 /* --- @kx_init@ --- *
590 * Arguments: @keyexch *kx@ = pointer to key exchange context
591 * @peer *p@ = pointer to peer context
592 * @keyset **ks@ = pointer to keyset list
594 * Returns: Zero if OK, nonzero if it failed.
596 * Use: Initializes a key exchange module. The module currently
597 * contains no keys, and will attempt to initiate a key
601 extern int kx_init(keyexch */*kx*/, peer */*p*/, keyset **/*ks*/);
603 /*----- Keysets and symmetric cryptography --------------------------------*/
605 /* --- @ks_drop@ --- *
607 * Arguments: @keyset *ks@ = pointer to a keyset
611 * Use: Decrements a keyset's reference counter. If the counter hits
612 * zero, the keyset is freed.
615 extern void ks_drop(keyset */*ks*/);
617 /* --- @ks_gen@ --- *
619 * Arguments: @const void *k@ = pointer to key material
620 * @size_t x, y, z@ = offsets into key material (see below)
621 * @peer *p@ = pointer to peer information
623 * Returns: A pointer to the new keyset.
625 * Use: Derives a new keyset from the given key material. The
626 * offsets @x@, @y@ and @z@ separate the key material into three
627 * parts. Between the @k@ and @k + x@ is `my' contribution to
628 * the key material; between @k + x@ and @k + y@ is `your'
629 * contribution; and between @k + y@ and @k + z@ is a shared
630 * value we made together. These are used to construct two
631 * pairs of symmetric keys. Each pair consists of an encryption
632 * key and a message authentication key. One pair is used for
633 * outgoing messages, the other for incoming messages.
635 * The new key is marked so that it won't be selected for output
636 * by @ksl_encrypt@. You can still encrypt data with it by
637 * calling @ks_encrypt@ directly.
640 extern keyset *ks_gen(const void */*k*/,
641 size_t /*x*/, size_t /*y*/, size_t /*z*/,
644 /* --- @ks_tregen@ --- *
646 * Arguments: @keyset *ks@ = pointer to a keyset
648 * Returns: The time at which moves ought to be made to replace this key.
651 extern time_t ks_tregen(keyset */*ks*/);
653 /* --- @ks_activate@ --- *
655 * Arguments: @keyset *ks@ = pointer to a keyset
659 * Use: Activates a keyset, so that it can be used for encrypting
663 extern void ks_activate(keyset */*ks*/);
665 /* --- @ks_encrypt@ --- *
667 * Arguments: @keyset *ks@ = pointer to a keyset
668 * @buf *b@ = pointer to input buffer
669 * @buf *bb@ = pointer to output buffer
671 * Returns: Zero if OK, nonzero if the key needs replacing. If the
672 * encryption failed, the output buffer is broken and zero is
675 * Use: Encrypts a block of data using the key. Note that the `key
676 * ought to be replaced' notification is only ever given once
677 * for each key. Also note that this call forces a keyset to be
678 * used even if it's marked as not for data output.
681 extern int ks_encrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
683 /* --- @ks_decrypt@ --- *
685 * Arguments: @keyset *ks@ = pointer to a keyset
686 * @buf *b@ = pointer to an input buffer
687 * @buf *bb@ = pointer to an output buffer
689 * Returns: Zero on success, or nonzero if there was some problem.
691 * Use: Attempts to decrypt a message using a given key. Note that
692 * requesting decryption with a key directly won't clear a
693 * marking that it's not for encryption.
696 extern int ks_decrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
698 /* --- @ksl_free@ --- *
700 * Arguments: @keyset **ksroot@ = pointer to keyset list head
704 * Use: Frees (releases references to) all of the keys in a keyset.
707 extern void ksl_free(keyset **/*ksroot*/);
709 /* --- @ksl_link@ --- *
711 * Arguments: @keyset **ksroot@ = pointer to keyset list head
712 * @keyset *ks@ = pointer to a keyset
716 * Use: Links a keyset into a list. A keyset can only be on one list
717 * at a time. Bad things happen otherwise.
720 extern void ksl_link(keyset **/*ksroot*/, keyset */*ks*/);
722 /* --- @ksl_prune@ --- *
724 * Arguments: @keyset **ksroot@ = pointer to keyset list head
728 * Use: Prunes the keyset list by removing keys which mustn't be used
732 extern void ksl_prune(keyset **/*ksroot*/);
734 /* --- @ksl_encrypt@ --- *
736 * Arguments: @keyset **ksroot@ = pointer to keyset list head
737 * @buf *b@ = pointer to input buffer
738 * @buf *bb@ = pointer to output buffer
740 * Returns: Nonzero if a new key is needed.
742 * Use: Encrypts a packet.
745 extern int ksl_encrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
747 /* --- @ksl_decrypt@ --- *
749 * Arguments: @keyset **ksroot@ = pointer to keyset list head
750 * @buf *b@ = pointer to input buffer
751 * @buf *bb@ = pointer to output buffer
753 * Returns: Nonzero if the packet couldn't be decrypted.
755 * Use: Decrypts a packet.
758 extern int ksl_decrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
760 /*----- Administration interface ------------------------------------------*/
762 /* --- @a_warn@ --- *
764 * Arguments: @const char *fmt@ = pointer to format string
765 * @...@ = other arguments
769 * Use: Informs all admin connections of a warning.
772 extern void a_warn(const char */*fmt*/, ...);
774 /* --- @a_create@ --- *
776 * Arguments: @int fd_in, fd_out@ = file descriptors to use
780 * Use: Creates a new admin connection.
783 extern void a_create(int /*fd_in*/, int /*fd_out*/);
785 /* --- @a_quit@ --- *
791 * Use: Shuts things down nicely.
794 extern void a_quit(void);
796 /* --- @a_daemon@ --- *
802 * Use: Informs the admin module that it's a daemon.
805 extern void a_daemon(void);
807 /* --- @a_init@ --- *
809 * Arguments: @const char *sock@ = socket name to create
813 * Use: Creates the admin listening socket.
816 extern void a_init(const char */*sock*/);
818 /*----- Peer management ---------------------------------------------------*/
820 /* --- @p_txstart@ --- *
822 * Arguments: @peer *p@ = pointer to peer block
823 * @unsigned msg@ = message type code
825 * Returns: A pointer to a buffer to write to.
827 * Use: Starts sending to a peer. Only one send can happen at a
831 extern buf *p_txstart(peer */*p*/, unsigned /*msg*/);
833 /* --- @p_txend@ --- *
835 * Arguments: @peer *p@ = pointer to peer block
839 * Use: Sends a packet to the peer.
842 extern void p_txend(peer */*p*/);
846 * Arguments: @peer *p@ = pointer to peer block
847 * @buf *b@ = buffer containing incoming packet
851 * Use: Handles a packet which needs to be sent to a peer.
854 extern void p_tun(peer */*p*/, buf */*b*/);
856 /* --- @p_interval@ --- *
862 * Use: Called periodically to do tidying.
865 extern void p_interval(void);
867 /* --- @p_stats@ --- *
869 * Arguments: @peer *p@ = pointer to a peer block
871 * Returns: A pointer to the peer's statistics.
874 extern stats *p_stats(peer */*p*/);
876 /* --- @p_ifname@ --- *
878 * Arguments: @peer *p@ = pointer to a peer block
880 * Returns: A pointer to the peer's interface name.
883 extern const char *p_ifname(peer */*p*/);
885 /* --- @p_addr@ --- *
887 * Arguments: @peer *p@ = pointer to a peer block
889 * Returns: A pointer to the peer's address.
892 extern const addr *p_addr(peer */*p*/);
894 /* --- @p_init@ --- *
896 * Arguments: @unsigned port@ = port number to listen to
900 * Use: Initializes the peer system; creates the socket.
903 extern void p_init(unsigned /*port*/);
905 /* --- @p_port@ --- *
909 * Returns: Port number used for socket.
912 unsigned p_port(void);
914 /* --- @p_create@ --- *
916 * Arguments: @const char *name@ = name for this peer
917 * @struct sockaddr *sa@ = socket address of peer
918 * @size_t sz@ = size of socket address
920 * Returns: Pointer to the peer block, or null if it failed.
922 * Use: Creates a new named peer block. No peer is actually attached
926 extern peer *p_create(const char */*name*/,
927 struct sockaddr */*sa*/, size_t /*sz*/);
929 /* --- @p_name@ --- *
931 * Arguments: @peer *p@ = pointer to a peer block
933 * Returns: A pointer to the peer's name.
936 extern const char *p_name(peer */*p*/);
938 /* --- @p_find@ --- *
940 * Arguments: @const char *name@ = name to look up
942 * Returns: Pointer to the peer block, or null if not found.
944 * Use: Finds a peer by name.
947 extern peer *p_find(const char */*name*/);
949 /* --- @p_destroy@ --- *
951 * Arguments: @peer *p@ = pointer to a peer
955 * Use: Destroys a peer.
958 extern void p_destroy(peer */*p*/);
960 /* --- @p_first@, @p_next@ --- *
962 * Arguments: @peer *p@ = a peer block
964 * Returns: @peer_first@ returns the first peer in some ordering;
965 * @peer_next@ returns the peer following a given one in the
966 * same ordering. Null is returned for the end of the list.
969 extern peer *p_first(void);
970 extern peer *p_next(peer */*p*/);
972 /*----- Tunnel interface --------------------------------------------------*/
974 /* --- @tun_init@ --- *
980 * Use: Initializes the tunneling system. Maybe this will require
981 * opening file descriptors or something.
984 extern void tun_init(void);
986 /* --- @tun_create@ --- *
988 * Arguments: @tunnel *t@ = pointer to tunnel block
989 * @peer *p@ = pointer to peer block
991 * Returns: Zero if it worked, nonzero on failure.
993 * Use: Initializes a new tunnel.
996 extern int tun_create(tunnel */*t*/, peer */*p*/);
998 /* --- @tun_ifname@ --- *
1000 * Arguments: @tunnel *t@ = pointer to tunnel block
1002 * Returns: A pointer to the tunnel's interface name.
1005 extern const char *tun_ifname(tunnel */*t*/);
1007 /* --- @tun_inject@ --- *
1009 * Arguments: @tunnel *t@ = pointer to tunnel block
1010 * @buf *b@ = buffer to send
1014 * Use: Injects a packet into the local network stack.
1017 extern void tun_inject(tunnel */*t*/, buf */*b*/);
1019 /* --- @tun_destroy@ --- *
1021 * Arguments: @tunnel *t@ = pointer to tunnel block
1025 * Use: Destroys a tunnel.
1028 extern void tun_destroy(tunnel */*t*/);
1030 /*----- Other handy utilities ---------------------------------------------*/
1032 /* --- @mpstr@ --- *
1034 * Arguments: @mp *m@ = a multiprecision integer
1036 * Returns: A pointer to the integer's textual representation.
1038 * Use: Converts a multiprecision integer to a string. Corrupts
1042 extern const char *mpstr(mp */*m*/);
1044 /* --- @timestr@ --- *
1046 * Arguments: @time_t t@ = a time to convert
1048 * Returns: A pointer to a textual representation of the time.
1050 * Use: Converts a time to a textual representation. Corrupts
1054 extern const char *timestr(time_t /*t*/);
1056 /*----- That's all, folks -------------------------------------------------*/